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Are you in an area warm enough where you can tell that the AC is really working and not just bringing in cold outside air?
It may just be the photo, but UV dye usually has more of a yellow tint to it.
I just went out to the garage and looked at the can of Pentosin 11S...that dark green looks exactly like your photo of the droplets.
I'm betting it's PS fluid leaking from the shaft between the pump body and pulley.
Hey, yup...its pretty warm (85F), but I have not turned on the AC (and made sure the heat was on a bit since it wants to put the fan back on a bit when you start it). I was hoping to isolate it to just the PS fluid, but not sure if that is 100% effective.
The color is weird. Whatever is leaking is bright green (well mostly..I did see some yellowish spots). And I did add some 11S, which is bright green. So makes sense except whatever is in the reservoir is dark yellow. Could it be a combination of whatever was in there before and the recently added 11S that is not homogeneous? If it was homogeneous, then it seems the reservoir color should be the same as the leak color.
I was thinking the same thing about the PS leak location (between body and pulley)...but I checked multiple times and the PS pulley is dry (while the AC pulley was wet with green). Wouldn't there be a sign of fluid on the PS pulley? Can you think of a test for this like bonding a thin piece of plastic to the pulley face with silicone that would block/collect the fluid? That could be removed without harm to the pulley. Or maybe a thin piece of cardboard...seems low risk in the event that it came loose.
Hey, yup...its pretty warm (85F), but I have not turned on the AC (and made sure the heat was on a bit since it wants to put the fan back on a bit when you start it). I was hoping to isolate it to just the PS fluid, but not sure if that is 100% effective.
Earlier you said the AC was working. How do you know it works if you haven't turned it on? At 85º, you'll know within seconds if it's working or not. If it's low or out of refrigerant, a low pressure switch will keep it from pumping and destroying itself.
I turned it on for about 5 minutes the other day just to check...but for the other testing (hours of driving so far), I left it off. It wasn't blowing super cold, but seemed to work OK. In the past when the AC doesn't work (I had a refrig leak in the evaporator), it will usually blow hot air so its a pretty stark difference. But in any case, its been cleaned up and new fluid has been deposited multiple times since I checked to see if the AC was working.
Btw, I just checked and the 11S has a pretty unique smell. So if I can drive it for a decent amount I can probably collect enough to gather it up from the bottom plastic shield and see if the smell is consistent.
Last edited by AeroStress; 03-22-2024 at 01:10 AM.
Hmm...even though I am not sure its the PS pump, there is a decent chance it is. Also, when they put the new rack in, they had to replace the pump, but it was a used one since it would have taken too long to get a new one. But I saw there is a US reman pump (MAVAL) that isn't very expensive. Seems like a pretty easy job really since its a the bottom on the V6. I had my friend do the AC compressor and he had to move the pump to get to the compressor, which looked easy. The only difference it seems would be R&I the two lines.
This isn't adding up to me. When soaked up from a paper towel, the leaking fluid is quite different in color from clean 11S and the PS fluid from the reservoir. Also, the leaking fluid seems to have a dye in it and glows green in UV light, but the clean 11S and PS fluid from the reservoir don't glow green. Its a bit more of a blue. The first question is if the fluid from the reservoir could be different from whats in the lines/pump? In other words, does it all get circulated? If not, then this test isn't conclusive. But if we expect the PS to be circulated and consistent with the reservoir then it just doesn't seem like it could be PS fluid.
The next alternative is AC oil. A dye was added to the system a while back, but the compressor has been replaced...but I believe other components have oil them as well so at it circulates, it could all get mixed in. So this makes a lot of sense, with one glaring issue. The A/C definitely still works and I have not been running it at all (and fluid is still leaking). Its possible that even without the compressor on, it could leak just be turning the pulley I suppose (clutch not engaged). But it really seems like the refrigerant would have escaped before the oil would (smaller particles) and it shouldn't blow cold. Of course, the compressor may just lock up one day and that would be the answer.
Also, I checked the Porsche pink coolant and it homogenizes with water (expected) and presumably so would any other alternative color. Since the leaking fluid definitely does not mix with water, is not coolant. Also, the brake fluid has never dropped so its not that.
Thats an interesting thought. I do have Liquimoly engine oil, but not with UV (at least not intentionally). But mistakes happen so I pulled the cap and looked at it under UV. Nothing notable and the fluid is dark brown to the naked eye.
I just removed a cup of PS steering fluid from the reservoir (it was brown) and and filled it with 11S (green). So I will if that changes color (indicating its mixing). Depending on that result, it seems easy enough to pull the PS line and see if that fluid is consistent with what is leaking. The other test is to take the refrigerant out and pull a vacuum on the AC system. Last time (about 6 months ago) it held solid overnight. But I really don't want to mess with AC since I have had a lot of issues with it an its working now (but perhaps the writing is on the wall that it won't be soon).
EDIT: Drove the car for about 20 miles and the clean 11S fluid I put in the reservoir is now a brownish color...so it seems to be mixing with the system. So at this point, I don't think its PS fluid. The old reservoir fluid did not glow green under UV and the leaking fluid does. But I will change out the reservoir a couple times until its green again just for kicks and may as well get some clean fluid in there.
Last edited by AeroStress; 03-24-2024 at 11:52 AM.
When you replace PS fluid in the reservoir, that's about half of the PS fluid in the system. You have to drain and fill it 3-4 times if not more if you want the fluid to look clear without draining the rack and whatnot. That's what I've been doing in my Cayenne, lol.
For AC, do you run windshield defogger? That automatically engages AC compressor in all cars (without lighting up AC button).
Lastly, if the leaking fluid has dye in it, have you tried inspecting for the source under the hood? Might have to remove the engine undertray to get a good look.
Worth asking: could it be windshield washer fluid? That just looks too green to be Pentosin and it does not match your reservoir. You also have a leak in that system based on losing fluid, but this may be two leaks. When your buddy replaced the PS pump, did he use new banjo bolts?
try leaving it running at idle in the driveway and crawling around to see if you can see where things are coming from. Maybe they’ll drip and pool up?
When the seals started leaking on the AC compressor in my Audi S8, it was the lowest point of the system and leaked a lot of compressor oil and dye. Looked a lot like this.
When the seals started leaking on the AC compressor in my Audi S8, it was the lowest point of the system and leaked a lot of compressor oil and dye. Looked a lot like this.
Interesting..so the AC was still working for at least some amount of time while there was visible fluid? At this point, I am almost certain is compressor oil and dye...nothing else makes sense. The only thing that doesn't add up was that I theorized the AC would not be able to work if there was leaking oil. But if you are saying that is not true, then I think that is the answer. I can easily check the AC gages and remove the refrigerant (hence not under pressure)...but even then I am not sure that would be conclusive since maybe the oil could still leak under no load (just from the pulley rotating).
Libast did have a good point about the oil. The Lubrimoly Molygen oil has a flourescent look to it, not a separate UV additive. When fresh it does look very much like the oil in you pic but also that fluid looks very much like PAG compressor oil.
Weird...I am changing the oil tomorrow and looked my usual "Liqui Moly Leichtlauf High Tech SAE 5W-40". It is yellow to the naked eye, but glows green in UV. I plan on changing the oil tomorrow so I can see what color it is (its usually black to the naked eye). The color I see leaking is green to the naked eye..though sometimes yellowish in other places (so its possible there are multiple leaks - one that is predominant one that is slow). I guess I just need to keep experimenting and watching to see.
EDIT: Just pulled the old engine oil out (Liqui Moly Leichtlauf High Tech SAE 5W-40). It was black and did not glow in the UV...so that isn't it. But for reference, when new, its yellow/brown and DOES glow under UV.
Last edited by AeroStress; 03-26-2024 at 08:44 AM.
At this point, I am 90+% confident its a leaking compressor. Nothing else would give off the growing green in UV light. PS fluid has been totally flushed out. The next compressor will be #4 within a year, but this time I will get one with a 2 year warranty. Or better yet, maybe I need to get the system flushed out from that stop leak that may be causing these issues. I am pretty sure #2 failed from the stop leak and maybe #3 (not sure). #1 may just be old age or moisture getting in (or low on oil).
03-21-2024, 09:33 PM
